Mounting Sights and Optics

Mounting Sights and Optics

Okay, I’m perusing the internet looking at forums about “how to set up your AR rifle,” and I come across a topic that seems confusing to some. As someone who fell prey to misnomers on this topic, I figured I’d chime in and see if we here at American Marksman could help remove some confusion. The three most popular types of targeting devices out there are iron sights, scopes, and red dots. Let’s look at each one and what they bring to the table.

Iron Sights

Iron sights are some of the most basic and common sights out there. Most firearms come with these pre-installed, although many ARs do not anymore, to give the end user more options to personalize their firearm.

The basic premise of these types of sights is that you would have a hole or window to look through at the rear of your firearm and a post in the front that you will center in your sight picture. They are highly reliable when adjusted correctly since no technology can go wrong. They have no lenses or batteries and tend to be very sturdy. 

Heckler & Koch MP5 iron sights

Hooded post viewed through an aperture of the rotating drum rear sight on a Heckler & Koch MP5.

Mounting these, you would place the sight with the window at the rear of the firearm closest to your eye and the post at the muzzle end of the firearm. Spacing them as far apart as you can creates the most accurate sighting system possible with these. 

Horizontal adjustments are made on the rear sight, and vertical adjustments are made on the front view. While offering no magnification, these sights are what many of us start with, and they can be very effective if you focus on the front sight in your sight picture.


Scopes are also very familiar to many of us as this is what we see hunters using. They offer increased magnification and can help you reach targets at greater distances with greater accuracy. 

While they are more susceptible to damage than iron sights, modern scopes are still reasonably robust. Some out there have batteries, but most can function adequately without battery power. 

hunting scope eye relief

Hunting scope on rifle chambered in 7.62x51.

Placement on the rifle is dependent on the eye relief required. Generally, most scopes should be placed on the rifle about 3.5 inches away from your eye (recommended eye relief specifications for your scope should be in your user manual). Failure to set the proper eye relief can result in a blurry or difficult target image, or worse—getting “kissed by the scope.”

Red Dots

Okay, so this is the one I and many others have fallen prey to confusion from reading firearms-related forums, and there still seems to be a lot of confusion on the topic. Similar to the advice about mounting your rifle scope, you might consider mounting a red dot with similar eye relief. You can, and many people do, and it works for them. But remember, a red dot doesn’t require eye relief like a scope does.

Red dot sights are designed to be used with both eyes open to give you an unobstructed field of view. Mounting a red dot close to your eye restricts your field of view, which is why many people recommend mounting them further down the rail.

red dot sight with close eye relief

Shooter with a close-mounted red dot sight.

You should not mount them on the handguard as that can cause issues with accuracy and a requirement to re-zero if you ever remove the handguard, e.g., cleaning, mounting accessories, or adjustments. 

Mounting red dot sights further forward also leaves you room to mount a magnifier closer to your eye if you choose to explore that option. Like scopes, magnifiers will have a recommended eye relief setting, so it needs to be closer to your eye.

red dot sight with far eye relief

Shooter with a far-mounted red dot sight.

When I started shooting with red dots, I mounted it close to my eye. It seemed odd to me when I moved it forward on the firearm, but now that I’ve shot it that way a few times, I’ve discovered I like it better and seem more accurate and aware of my surroundings.

So, some of the things I mentioned are facts (eye relief, for example), but others are all personal preferences. How and where do you mount your optics? Drop a comment below and let the community know what’s working for you!



With over two decades of experience in both civilian and military marksmanship programs, Teeps has developed a profound passion for shooting. Not only does he find great joy in introducing newcomers to the sport, but also continually seeks to expand his repertoire in the pursuit of shooting excellence.

Add Comment